Keggin型多金属氧酸盐催化醛与乙酸酐合成1,1-二乙酸酯

Synthesis of 1.1-diacetates under solvent-free by the Keggin Type Polyoxometalate

合成了一系列具有Keggin结构的MxPW12O40.nH2O和MxPMo12O40.nH2O多金属氧酸盐(其中,M=Fe、Mn、Ni、Cu、Zn;x=1、1.5),采用傅里叶变换红外光谱和X射线衍射等方法对其结构进行了表征;考察了醛与酸酐的摩尔比、催化剂用量、反应时间等反应条件对缩醛反应的影响.在优化条件下即FePW12O40用量0.034 mmol,反应时间5 min,n(aldehyde)∶n(Acetic Anhydrid)=1∶3时,以59.2%～94.9%的收率生成相应的1,1-二乙酸酯.

A series of Keggin type heteropoly acids were synthesized.Their FT-IR and X-ray spectroscopy indicated that the catalyst structures were Keggin type.1,1-diacetates was efficiently synthesized over MxPW12O40·nH2O and MxPMo12O40·nH2O catalysts（M=Fe、Mn、Ni、Cu、Zn;x=1、1.5）.Experimental results showed that a series of aldehydes could react with acetic anhydride to produce corresponding 1,1-diacetates at room temperature under solvent-free conditions by using heteropoly acid as catalyst,Among the tested catalysts.FePW12O40 is the best one and under optimum conditions,i.e.,FePW12O40 catalyst amount,0.034 mmol;reaction time 5 min,molar ratio of Aldehyde and Acetic Anhydride=1： 3,and 59.2%~94.9% yield of the corresponding 1,1-diacetates could be obtained.